Activation of the ryanodine receptor Ca2+ release channel of sarcoplasmic reticulum by a novel scorpion venom.
Activation of the ryanodine receptor Ca2+ release channel of sarcoplasmic reticulum by a novel scorpion venom.
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DOI：
10.1016/s0021-9258(18)54969-3
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发表时间：
1991-10
期刊：
影响因子：
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通讯作者：
H. Valdivia;O. Fuentes;R. El-Hayek;J. Morrissette;R. Coronado
中科院分区：
文献类型：
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作者：
H. Valdivia;O. Fuentes;R. El-Hayek;J. Morrissette;R. Coronado
我们确定了一个肽馏分从蝎子Butothotus hottentota的毒液刺激结合的[3 H]ryanodine骨骼和心脏肌浆网和脑微粒体的ryanodine受体的高度特异性的方式。活性集中在Mr 5，000 - 8，000的肽级分中。假设在这部分中有一个单一的活性肽，我们估计该肽与ryanodine受体相互作用的解离常数为20-30 nM。整个毒液和纯化的馏分激活骨骼ryanodine受体钙释放通道纳入平面脂质双层。毒液产生的平均开放时间增加了10倍，并诱导出现了一个长期持续的亚电导状态没有看到在控制。变化是可逆的，可以诱导的部分纯化的毒液馏分。这种新的蝎毒应有助于建立的作用，兰尼碱受体在启动细胞内Ca 2+释放横纹肌和非肌肉细胞含有功能的兰尼碱受体，如神经元和分泌细胞。
We identified a peptide fraction from the venom of the scorpion Buthotus hottentota that stimulated binding of [3H]ryanodine to ryanodine receptors of skeletal and cardiac sarcoplasmic reticulum and brain microsomes in a highly specific manner. Activity was concentrated in a peptide fraction of Mr 5,000-8,000. Assuming a single active peptide in this fraction, we estimated a dissociation constant of 20-30 nM for the interaction of the peptide with the ryanodine receptor. The whole venom and the purified fraction activated skeletal ryanodine receptor Ca2+ release channels incorporated into planar lipid bilayers. The venom produced a 10-fold increase in the mean open time and induced the appearance of a long lasting subconductance state not seen in controls. Changes were reversible and could be induced by the partially purified venom fraction. This novel scorpion venom should be helpful in establishing the role of ryanodine receptors in the initiation of intracellular Ca2+ release in striated muscle and in nonmuscle cells containing functional ryanodine receptors such as neurons and secretory cells.